What It Really Means When You Have A Dark Line On Your Fingernails

Fingernails see us through thick and thin, literally. Hard or brittle, long or short, the natural covering of our nail beds gives us outward clues about our inner health. Are your nails trying to tell you something? Pay attention to discoloration. Nail lines aren't uncommon, but they can be alarming. These blemishes differ by width, color, and how many nails are affected. If no physical damage caused the new lines, however, take note.

Healthline described tiny dark spots, called splinter hemorrhages, that occur when blood vessels break under the nail bed. These minor lines are not a health crisis. One report describes other black or brown lines in the nails as Hutchinson's sign, a symptom connected with melanoma and other cancers. Melanoma is detectable by moles that increase in size on the skin. Dark lines in the nails could also be melanonychia, caused by an excess of melanin appearing in people of African descent. These lines link to more serious concerns depending on whether they're from an increase of melanin or pigment cells (via Healthline).

Unusual nail blemishes highlight a number of things. Berkeley Wellness says fingernails show low oxygen levels and even heart conditions. Pigments in the nail may reveal reactions to certain medications. In an article for Aurora Health Center, dermatologist Katherine R. Garrity explained that discolored nails can also result from psoriasis, fungal infections, or thyroid problems.

According to Healthline, if "over two-thirds of the nail plate is discolored" or the nail becomes completely deformed, you should see a dermatologist. Additionally, if the nail marks are accompanied by fatigue, fever, joint pain, or rashes on the skin, talk with your doc immediately (via Healthline). Dermatologists, podiatrists, and primary care providers will consider age and family history before conducting further testing for a proper diagnosis.

The types of lines you see in your nails can provide you with general insight into your overall health. Some lines are harmless, while others signal potential issues. Don't hesitate to reach out to a medical professional if you have concerns.